Thermostat for a heatpump/dehumidifier

[scotsman]

I just had installed a Trane/Mitsubishi P-series ducted mini-split (TRUZA0301HA70NA) with a dehumidifier (Envirowise 70V). In order to work with my Nest thermostat my installer also put in a PAC-US444CN-1 thermostat controller interface.
 
I have been reading that this isn’t the best way to control a variable speed heat pump as the nest is really better with a staged system, and I have found that the behavior of the dehumidifier is erratic (it doesn’t seem to measure humidity very well)
 
Am I doing the right  thing here or is there a better solution?
 
I need something that is smart home compatible.

 

[picta]

The best thermostat for humidity control that I know of is Omnistat2000 from Leviton, which unfortunately has been discontinued. You may still be able to find it on ebay, at least the wired version. If do not have a communication wire ran into the thermostat location, then you'd need a zigbee version that may be harder to find and it requires a zigbee controller.